jpg vs png

rustbucket

I'm trying to optimize my game size (ipad 3 retina weighing in at 47mb) and I was wondering if there are any graphic format changes I should make. Right now 90% of the assets are PNG 24 but I could probably save considerable amount of space going jpg. It's my understanding that GS will just change those to png during publish anyway so I'm not sure if it's worth the bother. Anyone have any tips on optimizing for size?

IsabelleK

Try ImageOptim, and ImageAlpha - these are amazing apps to reduce graphics size.
The first one runs automatically, and can compress all graphics at once. The other is more powerful, but you have to work on each graphic separately.

ericzingeler

Yes you can optimize your images if need be. I've published multiple apps that I've manually optimized myself. The best optimization you can do is simply convert all .png files that do NOT need to be transparent to .jpg and then manually import into your project directory. Here's how:

First, your files upon import into GameSalad are automatically converted to .png. It doesn't matter what file type it was before the import, it'll end up being .png after import. Just to be clear, images are not converted at time of publish, but instead at time of import.

Steps:

1. (prior to import) Convert all images that don't need to be transparent to .jpg. Play around and make them as small as possible.

2. Import them into GameSalad (drag into actor or image pane).

3. Save your GS project and quit the App.

4. Show Package Contents of your GS project file.

5. Open the images folder.

6. Delete all of the .png files that you plan to replace with the .jpg files.

7. Copy all of the replacing .jpg files into the same folder. Close folder.

8. Open the assets.xml file in the root of the project directory with a proper text editor (BBEdit, TextWrangler, ...).

9. Wrap the text so you can see what the heck is going on. Now you'll notice that this file contains the information for your images in the game.

10. Scroll to the bottom of the page. Near the bottom you can see the names of the images you recently imported into the game. It should be in chronological order from top to bottom.

11. Now you simply need to replace .png with .jpg in the names of the images you are replacing. Each image will be referenced twice thus you have 2 png to jpg text replacements per image.

12. The quickest way to replace the names is to import images you plan to replace all at once or in large groups. This way you can simply select a group of text and run a replace all.

Done.

zzap64

this is awesome, really helps me out with my mass of large images.
i'm using jpg's all the way as they are smaller in size than any of the PNG's, even after ImageAlpha.
The current way i'm making smaller jpg's is when I 'save as' in Photoshop its asks for the JPG quality level...and i just reduce down.... is this the best way ?
thanks.

LumpApps

@zzap64 no, the best way is to choose "save for web and devices" (In the file menu).